The present invention relates to a semiconductor device and a power source device using the same, and, for example, relates to a technique effectively applied to a switching power source device converting a high voltage to a low voltage.
For example, Japanese Patent Laid-Open No. 2008-17620 (Patent Document 1) describes a semiconductor device wherein a power MOSFET, a drive circuit driving the same, and a control circuit transmitting a switching control signal to the drive circuit are mounted in one package (FIG. 1, FIG. 2).
Japanese Patent Laid-Open No. 2008-136307 (Patent Document 2) shows a DC-DC converter based on a comparator method of controlling an output voltage by adjusting a switching frequency. Japanese Patent Laid-Open No. 2006-211760 (Patent Document 3) shows a synchronous rectification type switching regulator capable of detecting a reverse flow flowing through an inductor at a light load.